No
645 becomes 650 when rounded to the nearest ten
645 becomes 600 when rounded to the nearest hundred
For this case we make a rule of three:
jar ---------------> 
pizza
x -----------------------------------------> 1 pizza
Where the variable "x" represents the amount of sauce jars to make a pizza.
So, you need 
jars of sauce to make a pizza.
Answer:
Slope = (y2-y1) / (x2-x1)
= (-4-20) / (6-4)
= (-24) / (2)
= (-12)
The slope of the line is (-12)
Ax + 3 = 7 - bx .....add bx to both sides
ax + bx + 3 = 7 ...subtract 3 from each side
ax + bx = 7 - 3
ax + bx = 4 ....factor out x
x(a + b) = 4 ...divide both sides by (a + b)
x = 4 / (a + b) <==
